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Alves FC, Donato P, Sherry AD, Zaheer A, Zhang S, Lubag AJM, Merritt ME, Lenkinski RE, Frangioni JV, Neves M, Prata MIM, Santos AC, de Lima JJP, Geraldes CFGC. Silencing of Phosphonate-Gadolinium Magnetic Resonance Imaging Contrast by Hydroxyapatite Binding. Invest Radiol 2003; 38:750-60. [PMID: 14627892 DOI: 10.1097/01.rli.0000084891.15996.0f] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
RATIONALE AND OBJECTIVES GdDOTP5- is a highly charged, bone-seeking paramagnetic complex that could potentially detect bone lesions by magnetic resonance imaging (MRI). To date, its pharmacokinetics, effects on organ relaxivity, and interaction with hydroxyapatite (HA) has not been described. METHODS Liver, kidney, and bone MRI images were obtained on male white rabbits after the administration of GdDOTP5- or a gold standard MRI contrast agent, GdDTPA2-. Parallel in vitro experiments quantified the effect of HA binding on GdDOTP5- -induced changes in relaxivity. RESULTS The 2 compounds showed similar MRI enhancements in visceral tissues, but no enhancement of bone was evident with GdDOTP5- despite confirmation of bone and HA binding of the radioactive 153SmDOTP5- and 111InDOTP5- derivatives. In vitro experiments demonstrated that GdDOTP5--induced changes in relaxivity were silenced upon HA binding but could be recovered by acid elution of the complex. CONCLUSIONS HA binding assays revealed that GdDOTP5- is essentially MR silent when bound to bone, likely because of the exclusion of all outer sphere water molecules from the surface of the complex. These data suggest a novel strategy for creating highly sensitive, switchable MRI contrast agents.
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Walz R, Castro RMRPS, Velasco TR, Alexandre V, Lopes MH, Leite JP, Santos AC, Assirati JA, Wichert-Ana L, Terra-Bustamante VC, Bianchin MM, Maciag PC, Ribeiro KB, Guarnieri R, Araújo D, Cabalero O, Moura R, Salim ACM, Kindlmann K, Landemberger MC, Marques W, Fernandes RMF, Serafini LN, Machado HR, Carlotti CG, Brentani RR, Sakamoto AC, Martins VR. Surgical outcome in mesial temporal sclerosis correlates with prion protein gene variant. Neurology 2003; 61:1204-10. [PMID: 14610121 DOI: 10.1212/01.wnl.0000096940.92986.02] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) is the most common surgically remediable epileptic syndrome. Ablation of the cellular prion protein (PrP(c)) gene (PRNP) enhances neuronal excitability of the hippocampus in vitro and sensitivity to seizure in vivo, indicating that PrP(c) might be related to epilepsy. OBJECTIVE To evaluate the genetic contribution of PRNP to MTLE-HS. METHODS The PRNP coding sequence of DNA from peripheral blood cells of 100 consecutive patients with surgically treated MTLE-HS was compared to that from a group of healthy controls adjusted for sex, age, and ethnicity (n = 180). The presence of PRNP variant alleles was correlated with clinical and presurgical parameters as well as surgical outcome. RESULTS A variant allele at position 171 (Asn-->Ser), absent in controls, was found in heterozygosis (Asn171Ser) in 23% of patients (p < 0.0001). The PRNP genotypes were not correlated with any clinical or presurgical data investigated. However, patients carrying the Asn171Ser variant had a five times higher chance of continuing to have seizures after temporal lobectomy (95% CI 1.65 to 17.33, p = 0.005) than those carrying the normal allele. At 18 months after surgery, 91.8% of patients with the normal allele at codon 171 were seizure free, in comparison to 68.2% of those carrying Asn171Ser (p = 0.005). CONCLUSIONS The PRNP variant allele Asn171Ser is highly prevalent in patients with medically untreatable MTLE-HS and influences their surgical outcome. The results suggest that the PRNP variant allele at codon 171 (Asn171Ser) is associated with epileptogenesis in MTLE-HS.
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de Araujo DB, Tedeschi W, Santos AC, Elias J, Neves UPC, Baffa O. Shannon entropy applied to the analysis of event-related fMRI time series. Neuroimage 2003; 20:311-7. [PMID: 14527591 DOI: 10.1016/s1053-8119(03)00306-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Event-related functional magnetic resonance imaging (ER-fMRI) refers to the blood oxygen level-dependent (BOLD) signal in response to a short stimulus followed by a long period of rest. These paradigms have become more popular in the last few years due to some advantages over standard block techniques. Most of the analysis of the time series generated in such exams is based on a model of specific hemodynamic response function. In this paper we propose a new method for the analysis of ER-fMRI based in a specific aspect of information theory: the entropy of a signal using the Shannon formulation, which makes no assumption about the shape of the response. The results show the ability to discriminate between activated and resting cerebral regions for motor and visual stimuli. Moreover, the results of simulated data show a more stable pattern of the method, if compared to typical algorithms, when the signal to noise ratio decreases.
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Uchida RR, Del-Ben CM, Santos AC, Araújo D, Crippa JA, Guimarães FS, Graeff FG. Decreased left temporal lobe volume of panic patients measured by magnetic resonance imaging. Braz J Med Biol Res 2003; 36:925-9. [PMID: 12845380 DOI: 10.1590/s0100-879x2003000700014] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Reported neuroimaging studies have shown functional and morphological changes of temporal lobe structures in panic patients, but only one used a volumetric method. The aim of the present study was to determine the volume of temporal lobe structures in patients with panic disorder, measured by magnetic resonance imaging. Eleven panic patients and eleven controls matched for age, sex, handedness, socioeconomic status and years of education participated in the study. The mean volume of the left temporal lobe of panic patients was 9% smaller than that of controls (t21 = 2.37, P = 0.028). In addition, there was a trend (P values between 0.05 and 0.10) to smaller volumes of the right temporal lobe (7%, t21 = 1.99, P = 0.06), right amygdala (8%, t21 = 1.83, P = 0.08), left amygdala (5%, t21 = 1.78, P = 0.09) and left hippocampus (9%, t21 = 1.93, P = 0.07) in panic patients compared to controls. There was a positive correlation between left hippocampal volume and duration of panic disorder (r = 0.67, P = 0.025), with recent cases showing more reduction than older cases. The present results show that panic patients have a decreased volume of the left temporal lobe and indicate the presence of volumetric abnormalities of temporal lobe structures.
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Tartaglia MC, Narayanan S, De Stefano N, Arnaoutelis R, Antel SB, Francis SJ, Santos AC, Lapierre Y, Arnold DL. Choline is increased in pre-lesional normal appearing white matter in multiple sclerosis. J Neurol 2002; 249:1382-90. [PMID: 12382153 DOI: 10.1007/s00415-002-0846-6] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Our aim was to determine if the resonance intensity of choline-containing compounds (Cho) measured using proton magnetic resonance spectroscopy (MRS) was increased in pre-lesional normal appearing white matter (NAWM) in patients with multiple sclerosis (MS) relative to NAWM that remained stable in subsequent scans. BACKGROUND The Cho peak in MR spectra is associated with membrane phospholipids and increases in acute MS plaques, possibly even before the appearance of MRI-visible MS lesions. METHODS Three combined proton MRI and MRS imaging examinations of the corpus callosum and adjacent periventricular white matter were performed on 12 MS patients at intervals of 6 months. Proton density (PD) images were visually matched across 3 time points and the lesion volume in each voxel of the volume of interest was determined. The voxels were subdivided into four groups based on the presence or absence of lesion at baseline and change or no change in lesion volume on the subsequent scan. RESULTS We found a significantly higher baseline Cho/Creatine (Cr) ratio in NAWM voxels that displayed MRI visible lesions 6 months later than NAWM voxels that remained unchanged (1.57 +/- 0.30 and 1.37 +/- 0.33, respectively, p < 0.001). The 12-month interval data revealed similar pre-lesional elevated Cho/Cr, (1.51 +/- 0.29 versus 1.39 +/- 0.32, p = 0.009). Voxels that contained lesion at baseline and increased in lesion volume at 6 months also showed a significantly higher Cho/Cr ratio than those whose lesion volume did not change (1.60 +/- 0.32 and 1.49 +/- 0.36, respectively, p = 0.043). CONCLUSIONS The results of this study are consistent with focal pre-lesional myelin membrane pathology in the NAWM at least 12 months before lesions become visible on conventional MRI. This could reflect altered myelin chemistry or the presence of inflammation as seen in experimental allergic encephalomyelitis.
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Prata MIM, Santos AC, Neves M, Geraldes CFGC, de Lima JJP. (153)Sm(3+) and (111)In(3+) DTPA derivatives with high hepatic specificity: in vivo and in vitro studies. J Inorg Biochem 2002; 91:312-9. [PMID: 12121790 DOI: 10.1016/s0162-0134(02)00417-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Two DTPA derivatives, a mono-amide derivative containing an iodinated synthon, DTPA-IOPsp (L(1)) and the ligand DTPA(BOM)(3) (BOM=benzyloxymethyl) (L(2)), radiolabelled with (153)Sm(3+) and (111)In(3+), were studied as potential hepatospecific gamma scintigraphic agents. In vivo studies with Wistar rats show that the main excretory pathway for all the chelates studied is the hepatobiliary system. The complexes of L(2) show even greater hepatobiliary specificity than L(1), perhaps as a consequence of longer blood circulation times due to their strong affinity towards HSA. The (153)Sm(3+) chelates are also more hepatospecific than the corresponding (111)In(3+) chelates. The La(3+) and In(3+) chelates of L(1) and L(2) show some structural and dynamic differences in aqueous solution, as studied by (1)H NMR spectroscopy. While only two nona-coordinated isomers were observed for the La(3+) complexes with both ligands, its number is much larger in the In(3+) complexes, with both octa- and hepta-coordinated species (with unbound side arms), as well as structural isomers for each coordination number.
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Eisenwiener KP, Prata MIM, Buschmann I, Zhang HW, Santos AC, Wenger S, Reubi JC, Mäcke HR. NODAGATOC, a new chelator-coupled somatostatin analogue labeled with [67/68Ga] and [111In] for SPECT, PET, and targeted therapeutic applications of somatostatin receptor (hsst2) expressing tumors. Bioconjug Chem 2002; 13:530-41. [PMID: 12009943 DOI: 10.1021/bc010074f] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A monoreactive NOTA (1,4,7-triazacyclononane-1,4,7-triacetic acid) derived prochelator (1-(1-carboxy-3-carbo-tert-butoxypropyl)-4,7-(carbo-tert-butoxymethyl)-1,4,7-triazacyclononane (NODAGA(tBu)(3))) was synthesized in five steps with an overall yield of 21%. It is useful for the coupling to the N-terminus of peptides on solid phase and in solution; it was coupled to [Tyr3]-octreotide (TOC) on solid phase, and the resulting peptide, NODAGA-Tyr3-octreotide (NODAGATOC), was labeled with the radiometals 111In and 67Ga in high yields and good specific activities. [67Ga]- and [111In]-NODAGA-Tyr3-octreotide appear to be useful to visualize primary tumors and metastases which express somatostatin receptors subtype 2 (sstr2), such as neuroendocrine tumors, because of their high affinity to this receptor subtype with IC(50) = 3.5 +/- 1.6 nM and 1.7 +/- 0.2 nM, respectively. NODAGATOC could be used as a SPECT and PET tracer, when labeled with 111In, 67Ga, or 68Ga, and even for therapeutic applications. Surprisingly, [111In]-NODAGATOC shows 2 times higher binding affinity to sstr2, but also a factor of 4 higher affinity to sstr5 compared to [67Ga]-NODAGATOC. [67Ga]-NODAGATOC is very stable in serum and rat liver homogenate. There is no difference in the rate of internalization into AR4-2J rat pancreatic tumor cells; both radioligands are highly internalized, at 4 h a 3 times higher uptake compared to [111In]-DOTA-Tyr3-octreotide ([111In]-DOTATOC) was found. The biodistribution of [67Ga]-NODAGATOC in AR4-2J tumor bearing nude mice is very favorable at short times after injection; there is fast excretion from all nontarget organs except the kidneys and high uptake in sst receptor rich organs and in the AR4-2J tumor. Again it is superior to [111In]-DOTATOC in this respect. The results indicate an improved biological behavior which is likely due to the fact that an additional spacer group separates the chelate from the pharmacophoric part of the somatostatin analogue.
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Hadzic A, Vloka JD, Santos AC. Research in regional anesthesia: objective versus subjective. Reg Anesth Pain Med 2001; 26:593-5. [PMID: 11707807 DOI: 10.1053/rapm.2001.26221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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84
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Gutierrez EB, Li HY, Santos AC, Lopes MH. Effectiveness of influenza vaccination in elderly outpatients in São Paulo city, Brazil. Rev Inst Med Trop Sao Paulo 2001; 43:317-20. [PMID: 11781600 DOI: 10.1590/s0036-46652001000600003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To investigate the effectiveness of the influenza vaccine in a population of elderly outpatients, we compared the occurrence and frequency of influenza like illness (ILI), respiratory illness and hospitalization in vaccinated and non-vaccinated subjects. All the outcomes were clinically defined. The two groups were similar with respect to demographics, health situation and habits. The influenza vaccine contributed to the protection of the elderly investigated, since the vaccinated subjects referred a significantly lower number of ILI than the non-vaccinated. There is a need for more studies about the effectiveness of the influenza vaccine in our country in elderly and other groups of our population.
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Hadzic A, Vloka JD, Santos AC, Schwartz AJ, Sanborn K, Birnbach DJ, Thys DM. Training requirements for peripheral nerve blocks. Anesthesiology 2001; 95:1303. [PMID: 11685013 DOI: 10.1097/00000542-200111000-00050] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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86
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Santos AC, DeArmas PI. Systemic toxicity of levobupivacaine, bupivacaine, and ropivacaine during continuous intravenous infusion to nonpregnant and pregnant ewes. Anesthesiology 2001; 95:1256-64. [PMID: 11684998 DOI: 10.1097/00000542-200111000-00033] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Levobupivacaine, the single levorotatory isomer of bupivacaine, is now available for clinical use. This study was undertaken to determine whether pregnancy affects the systemic toxicity of levobupivacaine and to compare the systemic toxicity of levobupivacaine with that of bupivacaine and ropivacaine. METHODS Chronically prepared nonpregnant and pregnant sheep were randomized to receive an intravenous infusion of 0.52% levobupivacaine, 0.52% bupivacaine, or 0.50% ropivacaine at a constant rate of 0.1 ml x kg(-1) x min(-1) until circulatory collapse. The investigators were blinded to the identity of the local anesthetic. Physiologic parameters, including cardiac rhythm, were monitored throughout the study. Arterial blood samples were obtained before infusion and at the onset of toxic manifestations. These were analyzed for total and free serum drug concentrations as well as arterial blood pH and gas tensions. RESULTS The doses of all three drugs required to produce convulsions were lower in pregnant than nonpregnant animals. However, as the infusion continued, there were no significant differences between pregnant and nonpregnant ewes in the dose of drug required to produce more advanced manifestations of toxicity: hypotension, apnea, and circulatory collapse. The mean cumulative dose and serum concentration at each toxic manifestation was lowest for bupivacaine, intermediate for levobupivacaine, and highest for ropivacaine in both pregnant and nonpregnant animals. For all three local anesthetics, there were no significant differences between pregnant and nonpregnant ewes in total and free serum drug concentrations, except that at circulatory collapse, these were higher in pregnant animals. CONCLUSIONS Pregnancy increases the risk of convulsions but not of more advanced manifestations of local anesthetic toxicity. The risk of toxicity is greatest with bupivacaine and least with ropivacaine. However, in actual clinical practice, the risk of systemic toxicity may also be affected by the relative potency and effectiveness of these drugs.
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Santos AC, Fontes F. [The Portuguese state and the challenges of (homo)sexuality]. REVISTA CRITICA DE CIENCIAS SOCIAIS 2001:173-194. [PMID: 20229660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Fonseca I, Queirós J, Santos MJ, Mendonça D, Henriques AC, Sarmento AM, Santos AC, Guimarães S, Pereira M. Hyperhomocysteinemia in renal transplantation: preliminary results. Transplant Proc 2000; 32:2602-4. [PMID: 11134723 DOI: 10.1016/s0041-1345(00)01803-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Leite JP, Terra-Bustamante VC, Fernandes RM, Santos AC, Chimelli L, Sakamoto AC, Assirati JA, Takayanagui OM. Calcified neurocysticercotic lesions and postsurgery seizure control in temporal lobe epilepsy. Neurology 2000; 55:1485-91. [PMID: 11094102 DOI: 10.1212/wnl.55.10.1485] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Several studies suggest that neurocysticercosis is the main cause of symptomatic epilepsy in developing countries. In such areas, calcified cysticercotic lesions (CCL) are frequently found in patients with complex partial seizures associated with hippocampal sclerosis (HS). The authors studied whether there are clinical and pathologic differences between HS patients with and without CCL. METHODS The authors determined the clinical and pathologic findings of 30 patients with HS and compared them with 32 patients with HS + CCL. Hippocampi from both groups were measured for fascia dentata Timm staining and cell density in hippocampal subfields. RESULTS In the HS + CCL group, single or multiple CCL were found in all lobes with no lobar predominance. An initial precipitating event occurred in 83.3% of HS and in 62.5% of HS + CCL. First complex partial seizure occurred at 10.1 years in HS and at 11.9 years in HS + CCL. No significant differences were found for fascia dentata Timm staining and hippocampal cell densities. Good postsurgery outcome (Engel I classification) did not differ between groups, with this result occurring in 76.6% of patients with HS and 81.2% of patients with HS + CCL. CONCLUSIONS The presence of CCL does not influence the clinical and pathologic profile of patients with hippocampal atrophy. Clinical histories and postsurgical outcomes were similar to those of patients with classic HS, suggesting that the CCL is probably, in this set of patients, a coincidental pathology and does not have a role in epileptogenesis.
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Prata MI, Santos AC, Bligh SW, Chowdhury AH, Geraldes CF, de Lima JJ. Characterization of (111)In(3+) complexes of DTPA amide derivatives: biodistribution and clearance studied by gamma imaging. Nucl Med Biol 2000; 27:605-10. [PMID: 11056377 DOI: 10.1016/s0969-8051(00)00127-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A large series of structurally related diethylenetriaminepentaacetic acid amide derivatives with different structures and lipophilic properties were synthesized and radiolabeled with (111)In(3+). Two of the more hydrophobic compounds studied ([(111)In]L(9) and [(111)In]L(10)) showed high affinity for human serum albumin (HSA). The biodistribution and clearance properties shown by all complexes upon injection in Wistar rats were followed by gamma imaging. The blood retention time of the chelates correlates better with their binding to HSA than with their hydrophilic/lipophilic ratio. Hydrophilic and negatively charged complexes undergo renal retention, while the majority of the lipophilic complexes are retained in the blood for a longer period of time and are cleared through the liver.
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Jordani MC, Santos AC, Prado IM, Uyemura SA, Curti C. Flufenamic acid as an inducer of mitochondrial permeability transition. Mol Cell Biochem 2000; 210:153-8. [PMID: 10976768 DOI: 10.1023/a:1007185825101] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
To assess the mechanism by which mitochondrial permeability transition (MPT) is induced by the nonpolar carboxylic acids, we investigated the effects of flufenamic acid (3'-trifluoromethyl diphenylamine-2-carboxylic acid, FA) on mitochondrial respiration, electrical transmembrane potential difference (delta psi), osmotic swelling, Ca2+ efflux, NAD(P)H oxidation and reactive oxygen species (ROS) generation. Succinate-energized isolated rat liver mitochondria incubated in the absence or presence of 10 microM Ca2+, 5 microM ruthenium red (RR) or 1 microM cyclosporin A (CsA) were used. The dose response-curves for both respiration release and delta psi dissipation were nearly linear, presenting an IC50 of approximately 10 microM and reaching saturation within 25-50 microM, indicating that FA causes mitochondrial uncoupling by a protonophoric mechanism. Within this same concentration range FA showed the ability to induce MPT in energized mitochondria incubated with 10 microM Ca2+, followed by delta psi dissipation and Ca2+ efflux, and even in deenergized mitochondria incubated with 0.5 mM Ca2+. ADP, Mg2+, trifluoperazine (TFP) and N-ethylmaleimide (NEM) reduced the extent of FA-promoted swelling in energized mitochondria by approximately one half, whereas dithiothreitol (DTT) slightly enhanced it. NAD(P)H oxidation and ROS generation (H2O2 production) by mitochondria were markedly stimulated by FA; these responses were partly prevented by CsA, suggesting that they may be implicated as both a cause and effect of FA-induced MPT. FA incubated with mitochondria under swelling assay conditions caused a decrease of approximately 40% in the content of protein thiol groups reacting with 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB). The present results are consistent with a ROS-intermediated sensitization of MPT by a direct or indirect FA interaction with inner mitochondrial membrane at a site which is in equilibrium with the NAD(P)H pool, namely thiol groups of integral membrane proteins.
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Lorenzo D, Atti-Serafini L, Santos AC, Frizzo CD, Paroul N, Paz D, Dellacassa E, Moyna P. Achyrocline satureioides essential oils from southern Brazil and Uruguay. PLANTA MEDICA 2000; 66:476-477. [PMID: 10909273 DOI: 10.1055/s-2000-8590] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The essential oils of the aerial parts of Achyrocline satureioides (D.C.) Lam., a regional medicinal plant, from different collection locations in the South of Brazil and Uruguay were examined by GC and GC-MS. Monoterpene and sesquiterpene hydrocarbons were the main fractions of both the oils from Brazil and Uruguay. The oxygenated monoterpenes and sequiterpenes were at much lower percentage in both samples. The Uruguayan samples have 1,8-cineole which is not present in the Brazilian samples and has not been reported in other samples from Brazil. The results indicated a high biodiversity of the native populations of A. satureioides.
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Prata MI, Santos AC, Geraldes CF, de Lima JJ. Structural and in vivo studies of metal chelates of Ga(III) relevant to biomedical imaging. J Inorg Biochem 2000; 79:359-63. [PMID: 10830889 DOI: 10.1016/s0162-0134(99)00232-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The solution chemistry and structure of the complex of the triazamacrocyclic ligand NOTP (1,4,7-triazacyclononane-1,4,7-tris(methylenephosphonate)) with Ga3+ in D2O have been investigated by 1H, 71Ga and 31P NMR spectroscopy. These NMR results show the presence of a 1:1 Ga(NOTP)3- complex, with a highly symmetrical, pseudo-octahedral geometry, possibly with a C3 axis. The 1H spectrum shows that the triazamacrocyclic chelate ring is very rigid, with all the ring protons non-equivalent. The complex is stable in aqueous solution in a wide pH range. Its high thermodynamic stability agrees well with previous results from biodistribution and gamma imaging studies in Wistar rats with 67Ga3+ chelates of triaza macrocyclic ligands, which showed that the neutral chelates 67Ga(NOTA) (where NOTA is 1,4,7-triazacyclononane-1,4,7-triacetate) and 67Ga(NOTPME) (where NOTPME is 1,4,7-triazacyclononane-1,4,7-tris(methylenephosphonate monoethylester)) have similar in vivo behaviour, with high stability and rapid renal excretion, but the high negatively charged 67Ga(NOTP)3- has a considerably slower kidney uptake and elimination.
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Bobby PD, Santos AC. Effect of prolonged asphyxia on skin blood flow in fetal lambs. Obstet Gynecol 2000; 95:607-11. [PMID: 10725499 DOI: 10.1016/s0029-7844(99)00644-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To determine the effect of a prolonged period of asphyxia on skin blood flow, a potential indicator of fetal cardiovascular responses to asphyxia, in the chronically catheterized fetal lamb. METHODS Eight chronically instrumented pregnant ewes were studied at 118 +/- 1 days' gestation. After a control period, fetal acid-base status was assessed and regional blood flows were determined with dye-labeled microspheres. Fetal asphyxia was then induced by partial umbilical cord occlusion, decreasing fetal arterial oxygen pressure to 15 torr while maintaining pH above 7.28. Fetal cardiovascular status was monitored continuously. Fetal acid base status was evaluated every 10-15 minutes during cord occlusion. Regional blood flow determinations were repeated after 90 minutes of stable asphyxia. Results are expressed as the mean +/- standard error. Student t test for paired data was used to compare hemodynamic, acid-base, and regional blood flow determinations before cord occlusion and after 90 minutes of asphyxia. RESULTS There was a significant increase in blood flow to the fetal scalp from a control value of 52 +/- 8 mL per minutes per 100 g to 175 +/- 30 mL per minute per 100 g at 90 minutes of asphyxia (P =.01). Similarly, there was an increase in blood flow to the skin overlying the fetal hindquarter from 39 +/- 12 mL per minute per 100 g during control to 153 +/- 47 mL per minute per 100 g at asphyxia (P =.038). CONCLUSION In the chronically instrumented fetal lamb, a 90-minute period of asphyxia produced by partial cord occlusion resulted in a significant increase in blood flow to the fetal skin.
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Moura G, Vilarinho L, Santos AC, Machado J. Organic compounds in the extrapalial fluid and haemolymph of Anodonta cygnea (L.) with emphasis on the seasonal biomineralization process. Comp Biochem Physiol B Biochem Mol Biol 2000; 125:293-306. [PMID: 10818264 DOI: 10.1016/s0305-0491(99)00192-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Bivalve mollusks, such as the freshwater mussel Anodonta cygnea, show seasonal changes in calcification. This cycle of calcification must either be a cause or a consequence for seasonal fluctuations in the organic composition of the animal's fluids, haemolymph and extrapallial fluid, the liquid media for biomineralization. We monitored the fluids of A. cygnea, throughout a 1-year cycle, for the presence of organic constituents, known to be important for biomineralization, such as proteins, glycosaminoglycans (GAGs) and hexosamines. Proteins were subjected to further study, namely through the total amino acid determination and fraction separation by agarose gel electrophoresis. GAG levels were fairly constant throughout the year, with a maximum concentration in July and a minimum in January, a feature also detected for glucosamine, although with higher fluctuations. Proteins showed highly increased concentrations during June and July, both in total amounts and individual fractions. All fractions showed similar trends throughout the year, with lowest general levels in October, the starting month of a period when some fractions were not detectable at all. All fractions ended this low period in May, when a sometimes-important increase could be detected. As to the total amino acid composition of the fluids, the general trend followed that of proteins, except for ornithine (Orn), a non-proteic amino acid. The overall fluctuations detected in the biological fluids of A. cygnea suggest that the main variation related to the calcification cycle must be quantitative, since no different compounds appear in specific periods, to achieve also specific results.
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96
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Gusmão Melo D, Pina-Neto JM, Acosta AX, Daniel J, de Castro V, Santos AC. Neuroimaging and echocardiographic findings in Sotos syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS 2000; 90:432-4. [PMID: 10706367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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97
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Lorenzo D, Dellacassa E, Atti-Serafini L, Santos AC, Frizzo C, Paroul N, Moyna P, Mondello L, Dugo G. Composition and stereoanalysis ofCymbopogon winterianus Jowitt oil from Southern Brazil. FLAVOUR FRAG J 2000. [DOI: 10.1002/1099-1026(200005/06)15:3<177::aid-ffj887>3.0.co;2-m] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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98
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Santos AC, Yamaoka Y, Graham DY, Sepulveda AR. Variability in the interpretation of microsatellite patterns with different electrophoretic conditions. Mol Pathol 1999; 52:302-4. [PMID: 10748882 PMCID: PMC395715 DOI: 10.1136/mp.52.5.302] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Microsatellite markers permit the analysis of microsatellite instability and loss of heterozygosity. Frequently, the allelotypes of microsatellites are interpreted in the presence of numerous bands in gels. The importance of different gel electrophoresis conditions in the interpretation of microsatellite patterns was tested. Microsatellite markers were used to amplify DNA from gastric cancer samples and adjacent gastric mucosa. Polymerase chain reaction (PCR) products were separated by electrophoresis through 7% polyacrylamide gels containing either 5.6 M urea and 32% formamide or 7 M urea. PCR reactions separated on urea/formamide gels resulted consistently in clear allele definition (one or two bands), whereas 7 M urea gels resulted in allele patterns that comprised multiple bands. Analysis of microsatellite abnormalities using nonformamide gels gave false negative results in just under a third of cases (four of 13). In conclusion, the interpretation of microsatellite alterations in cancer DNA is improved by using electrophoresis conditions that result in complete DNA denaturation, such as urea/formamide/acrylamide gel electrophoresis.
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99
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Sepulveda AR, Santos AC, Yamaoka Y, Wu L, Gutierrez O, Kim JG, Graham DY. Marked differences in the frequency of microsatellite instability in gastric cancer from different countries. Am J Gastroenterol 1999; 94:3034-8. [PMID: 10520865 DOI: 10.1111/j.1572-0241.1999.01453.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Previous studies have reported variable rates of microsatellite instability (MSI) in gastric cancer. We investigated the frequency of MSI in invasive gastric carcinoma of patients from three geographic regions. METHODS Genomic DNA from gastric cancer and nontumor tissue from 22 Korean, 20 Colombian, and 26 U.S. patients was amplified with five microsatellite markers. RESULTS MSI was more frequently seen in gastric cancer from Korea, affecting 50% of patients, in contrast with gastric cancers from the U.S. (7%) and Colombia (15%) (p = 0.003 and p = 0.03, respectively). MSI at one locus was significantly more frequent in gastric cancer from individuals >65 yr (p = 0.01). MSI was similarly associated with both diffuse and intestinal types of gastric cancer. CONCLUSIONS MSI affects the two major histological types of gastric cancer, and was more frequent in gastric cancer from Korea than in the other countries, suggesting that the relative importance of different pathways of gastric carcinogenesis may vary in diverse regions of the world.
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100
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Curti C, Mingatto FE, Polizello AC, Galastri LO, Uyemura SA, Santos AC. Fluoxetine interacts with the lipid bilayer of the inner membrane in isolated rat brain mitochondria, inhibiting electron transport and F1F0-ATPase activity. Mol Cell Biochem 1999; 199:103-9. [PMID: 10544958 DOI: 10.1023/a:1006912010550] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The effects of fluoxetine on the oxidative phosphorylation of mitochondria isolated from rat brain and on the kinetic properties of submitochondrial particle F1F0-ATPase were evaluated. The state 3 respiration rate supported by pyruvate + malate, succinate, or ascorbate + tetramethyl-p-phenylenediamine (TMPD) was substantially decreased by fluoxetine. The IC50 for pyruvate + malate oxidation was approximately 0.15 mM and the pattern of inhibition was the typical one of the electron-transport inhibitors, in that the drug inhibited both ADP- and carbonyl cyanide m-chlorophenylhydrazone (CCCP)-stimulated respirations and the former inhibition was not released by the uncoupler. Fluoxetine also decreased the activity of submitochondrial particle F1F0-ATPase (IC50 approximately 0.08 mM) even though K0.5 and activity of Triton X-100 solubilized enzyme were not changed substantially. As a consequence of these effects, fluoxetine decreased the rate of ATP synthesis and depressed the phosphorylation potential of mitochondria. Incubation of mitochondria or submitochondrial particles with fluoxetine under the conditions of respiration or F1F0-ATPase assays, respectively, caused a dose-dependent enhancement of 1-anilino-8-naphthalene sulfonate (ANS) fluorescence. These results show that fluoxetine indirectly and nonspecifically affects electron transport and F1F0)-ATPase activity inhibiting oxidative phosphorylation in isolated rat brain mitochondria. They suggest, in addition, that these effects are mediated by the drug interference with the physical state of lipid bilayer of inner mitochondrial membrane.
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